1. Field of the Invention
This invention relates to wireless telecommunications systems and methods of operation. More particularly, the invention relates to carrier selection in overlapping heterogeneous wireless telecommunication networks or base stations in homogenous networks.
2. Description of Prior Art
Today user""s can take advantage of multiple communication networks, particularly mobile voice communications heavily built out and overlapping in coverage. Such networks provide Advanced Mobile Phone Service (AMPS) using analog technology or digital technology using Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), Global Standard Mobile (GSM), etc.
The cell structure employed by such communication networks is designed to provide good communication capability within its coverage area. When communication networks compete, as is the case today with AMP, CDMA and TDMA options, the cell structure and coverage area overlaps. A user in a metropolitan area is likely to be within the coverage area of three or more communication networks. At any given location and time, dependent on load, position, building interference, any of these networks might provide the best service for a given user. With a protocol agile terminal, a user can obtain the desired communication at the best price. Additionally, since there is no universal coverage by any given network provider, the user may piece together xe2x80x9cuniversal coveragexe2x80x9d by taking advantage of all network build-outs rather than picking just one. As new protocols are invented, with less than universal applicability, (i.e., a protocol designed for skyscraper interference in a city), the user can take advantage of such protocols for which they are designed without losing the more general network connectivity. Moreover, network providers now have a way to balance load in their cell. If a cell is relatively idle, a provider can drop the price to entice more traffic. If high bandwidth for data communication is required or more profitable, a provider can an offer a higher bandwidth to the requesting device. Further, if a provider has heterogeneous subnetworks, a provider may offer service more seamlessly.
Prior art related to selective service management in wireless telecommunication networks, includes the following:
U.S. Pat. No. 5,625,877 issued Apr. 29, 1997, discloses a wireless air-link communication system which allows a user of an end-user communicating device, e.g., a cellular phone, computer, facsimile, to request the allocation of an aggregation of available air-link communication channels for wireless variable bandwidth across the air links at the demand of the user. Variable bandwidth for wireless communication increases the speed and efficiency of data transmission conventionally limited to fixed speeds because such transmissions have been across a single air link channel.
U.S. Pat. No. RE35, 916 issued Oct. 6, 1998, discloses a cellular telephone system that uses position of a mobile unit to make call management decisions. Call management includes selection of a cell site most appropriate for a call associated with a mobile unit. Selection is based on the geographic location of the mobile unit as opposed to the strength of the signal associated with the cell. The geographic location of the mobile unit is precisely determined using a satellite, e.g. Global Positioning System or its equivalent. Each mobile unit includes a GPS receiver that receives information from a geo-stationary satellite to determine the precise location of the mobile unit. The position information is relayed to the cell site initially managing the mobile unit. The mobile unit is handed off to a cell site that is most appropriate for the call. Initial selection of an entrance cell site is made based on signal strength, but further call management decisions are based on location of the mobile unit.
U.S. Pat. No. 5,818,814 issued Oct. 6, 1998 discloses a method and apparatus for synchronizing and controlling remote receivers. A mobile receiver is synchronized to one of a plurality of transmitters, each transmitter disposed in a separate zone and having a defined range. A common command channel is provided for both zones of which command information can be transmitted from the transmitters. Each of the transmitters is operable to transmit over the common command channel a carrier having a pulse stream at a frequency that is a harmonic of a predetermined, fundamental frequency. The pulse streams are synchronized with each other with at least two transmitters having different frequencies. Each of the pulses in each of the pulse streams is pulsed width modulated with command information associated with the associated transmitter. These various commands define the channel over which audio is to be transmitted. The channels can either be user-defined or they can be the function of the transmitter.
U.S. Pat. No. 5,878,344 issued Mar. 2, 1999, filed Feb. 24, 1994, discloses a system which automatically switches a user handset between a standard cellular radiotelephone mode of operation and enhanced cordless mode when the handsets are within range of pico cells that are interconnected to the public switch telephone network. Each pico cell is controlled via a framework of overlay cells that operate independently of the radio telephone network and use a unique control protocol on a small number of reserved cellular channels. Each pico cell consists of a spectrally dynamic, non-capturing, frequency agile, multiple purpose base station provided at customer selected locations to cooperate fully with the overlay cell framework. Each pico cell reduces traffic on the standard cellular radiotelephone network by independently handling registered handsets. An alternate line option module provides wireless local interconnect capability to selectively route call traffic between landlines and radiotelephone network. Service control units and host stations facilitate wireless activation in control of each pico cell and handset via the overlay.
None of the prior art disclose carrier selection in overlapping heterogeneous mobile wireless communication networks, particularly, where hand over of calls between heterogeneous network may be carried over a different set of frequencies with different protocols that require the mobile station to monitor the adjacent cells for hand off preparation.
An object of the invention is a wireless telecommunication system and method of operation providing users carrier selection in overlapping heterogeneous networks
Another object is enabling users to select a preferred carrier in overlapping heterogeneous network.
Another object is an internetwork command channel linked to users for carrier selection purposes.
Another object is a Central Selection Agency (CSA) determining carrier selection for a given user depending upon user requirements and network availability.
Another object is a shared command channel linking heterogeneous networks available to users for carrier selection.
Another object is enabling edge nodes in heterogeneous networks to mediate carrier selection for a user.
Another object is enhanced security for wireless calls on the originator""s end of the call.
These and other objects, features and advantages are achieved in a wireless telecommunication network selection system and method of operation which enables a user to obtain communication services in heterogeneous or homogeneous wireless networks using different protocols and frequencies at the most economical cost and bandwidth. A plurality of overlapping networks includes an internetwork command channel, a Central Selection Agency (CSA), a home location register, a visitor location register, and a user device positional location mechanism. The system and method may exist in several embodiments. In one embodiment, user devices equipped with Global Positioning System (GPS) determine a location. within fine limits. In placing a call a user device broadcasts an ID, location and connection capability requirements on a common command channel. When a base station for the command channel hears a request, the CSA and the home location register for the user are informed. The CSA using the location information and the connection capability/requirements determines which network and base stations are potential carriers. Based on user preferences (established by profile), the CSA assigns a network and base station to handle connection. The user device is informed and tunes to the appropriate network and protocol. For incoming calls, the calling party checks the home location register to determine the last known location. The called user device is informed by the command channel that a call is waiting. The called user device selects a network and base station to receive the call in a fashion similar to that of placing the call. A hand over of a user call between heterogeneous networks may be carried over a different set of frequencies with different protocols requiring the CSA to monitor the adjacent cells for handoff preparation. The user call is transferred to the heterogeneous network by the CSA according to the user profile and the preparation by the heterogeneous network to receive the call.